Basal cell carcinoma - New aspects of diagnosis and treatment

The incidence of basal cell carcinoma is increasing. New aspects of diagnos is and treatment are discussed in this thesis. Interferon can be used for the treatment of BCC. In paper I, 15 patients re ceived 13.5 x 10(6) IU of alfa-2b-interferon intralesionally. Four patients healed completely whereas a 75% reduction was seen in 5 cases, Intralesion al alfa-2b-interferon can reduce the number of excisions during Mobs Microg raphic Surgery. Topical photodynamic therapy involves the application of ALA on the skin. I n tumour cells selectively, formation of the photosensitizer Pp IX occurs. After 4 hours of occlusion of ALA the area is irradiated with light at a wa velength of 630 nm, Tumour cells are selectively destroyed during this proc edure. 144/157 SBCC healed in this series and 14/18 Mb Bowen (paper II). Th e method is only suited for thin BCCs as the result on thicker lesions is p oor (2/10 healed). The cosmetic result,vas generally good or excellent, Another way of utilising the tumour selectivity of Pp IX is for diagnostic purposes, Instead of illuminating with 630 nn, 365, 366 and 405 mm are used to induce a specific fluorescence. In the present paper (III), 50% of faci al BCCs with ill-defined borders could be completely visualised and another 23% partly outlined. The technique did not seem to work in 27% of the case s. The critical factor using ALA is probably the relatively poor penetrance th rough the skin. In paper IV, microdialysis is used for pharmacokinetic stud ies of ALA for the first time. The concentration of ALA increases rapidly i n lesional skin whereas there is virtually no penetration in healthy skin, Also, the blood perfusion in BCCs was investigated by means of laser Dopple r Perfusion Imager. The perfusion in skin overlying a BCC was 2.5 fold high er compared to normal skin. For BCCs with ill-defined borders Mohs Micrographic Surgery is generally re commended. Regarding Mobs Micrographic Surgery, Sweden is underserved as on ly 1% of BCCs are treated with Mobs Micrographic Surgery as opposed to 30% in the US. Consequently, the Swedish cases are probably more severe. The lo ng-term results are reported in paper V. Two hundred and twenty-eight tumou rs were followed for at least 5 years. The rate of recurrence was 8%. This figure is slightly higher than in international materials but surprisingly low considering the type of tumours.